package chapter04.example17;
//定义Animal类
class Animal{
    public void shout(){
        System.out.println("动物叫");
    }
}
//Dog类
class Dog extends Animal {
    //重写shout()方法
    public void shout(){
        System.out.println("汪汪汪汪");
    }
    public void eat(){
        System.out.println("吃骨头");
    }
}
//定义测试类
public class example17 {
    public static void main(String[] args){
        Animal a1=new Dog(); //通过向上转型实例化Animal对象
        System.out.println("Animal a1=new Dog():"+(a1 instanceof Animal));
        System.out.println("Animal a1=new Dog():"+(a1 instanceof Dog));
        Animal a2=new Animal();//实例化Animal对象
        System.out.println("Animal a2=new Dog():"+(a2 instanceof Animal));
        System.out.println("Animal a2=new Dog():"+(a2 instanceof Dog));
    }
}

